SECONDARY VOLTAGE RESTRICTING CIRCUIT OF POWER SOURCE CT

摘要

PROBLEM TO BE SOLVED: To protect an equipment connected to a secondary side by limiting an abnormal boosting of a voltage at the secondary side when excess current is permitted to flow to the primary side of power sourced CT. SOLUTION: TRIAC TA is connected in parallel between input terminals 1 and 2 and a snubber circuit consisting of a resistance R3 and a capacitor C2 is connected between the both terminals of TRIAC TA. A trigger current generating circuit consisting of Zener diodes ZD1 and ZD2 and the resistances R1 and R2 is provided between the secondary side terminals 1 and 2 of CT. When the voltage at an output side reaches the fixed voltage, TRIAC TA is operated and bypassing is executed between the input terminals 1 and 2.